This invention relates to the preparation of foodstuffs using microbiological processing with living cultures of microorganisms and particularly to a method and composition for protecting such cultures against attack by bacteriophage viruses.
In processes for preparing food using micro-organisms, a living culture of the microorganisms, capable of multiplying, is inoculated into the food which is to be prepared and living conditions appropriate to maintaining the desired activity of the microorganisms are created and maintained, for the duration of the desired activity, by adding nutrients and/or by adjusting the temperature, humidity and/or pH value.
Much industrial food preparation, such as for example fermentation and caseation, is carried out using microorganisms, such as bacteria, yeasts, fungi or algae. These microorganisms are subject to attack by bacteriophage viruses both in the cultures in which they are kept and also during their action on the foods. Such attacks can disrupt the conversion processes being carried out using the microorganisms.
Cultures used in the production of foodstuffs are attacked by bacteriophages and become spoiled unless one exercises great care. A culture must be protected from such attack both during storage in its inactive stages of growth as well as during its active stages of growth, that is, when it multiplies in use in processing. Spoiled cultures cannot be used to effect the desired microbiological process in the foodstuffs. Instead, other, undesirable, microorganisms, which penetrate into the foodstuffs from the outside or which are already contained in the foodstuffs, become effective and multiply accordingly. The effect of such other microorganisms is, as a rule, to cause the foodstuffs to spoil. Since microbiological processing of foodstuffs presupposes the use of special, selected pure cultures, attack and destruction by viruses such as phages is undersirable.